A chemist examines 17 sedimentary samples for lead concentration. The mean lead concentration for the sample data is 0.268 cc/cubic meter with a standard deviation of 0.069. Determine the 80% confidence interval for the population mean lead concentration. Assume the population is approximately normal. Step 1 of 2 : Find the critical value that should be used in constructing the confidence interval. Round your answer to three decimal places.

Answers

Answer 1

Answer:

The critical value that should be used in constructing the confidence interval is T = 1.337.

The 80% confidence interval for the population mean lead concentration is between 0.246 and 0.29 cc/cubic meter.

Step-by-step explanation:

We have the standard deviation for the sample, so we use the t-distribution to solve this question.

The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So

df = 17 - 1 = 16

90% confidence interval

Now, we have to find a value of T, which is found looking at the t table, with 16 degrees of freedom(y-axis) and a confidence level of [tex]1 - \frac{1 - 0.8}{2} = 0.9[/tex]. So we have T = 1.337, which is the crical value.

The margin of error is:

[tex]M = T\frac{s}{\sqrt{n}} = 1.337\frac{0.069}{\sqrt{17}} = 0.022[/tex]

In which s is the standard deviation of the sample and n is the size of the sample.

The lower end of the interval is the sample mean subtracted by M. So it is 0.268 - 0.022 = 0.246 cc/cubic meter

The upper end of the interval is the sample mean added to M. So it is 0.268 + 0.022 = 0.29 cc/cubic meter

The 80% confidence interval for the population mean lead concentration is between 0.246 and 0.29 cc/cubic meter


Related Questions

Consider the diagram and the paragraph proof below.

Given: Right △ABC as shown where CD is an altitude of the triangle
Prove: a2 + b2 = c2

Triangle A B C is shown. Angle A C B is a right angle. An altitude is drawn from point C to point D on side A B to form a right angle. The length of C B is a, the length of A C is b, the length of A B is c, the length of A D is e, the length of D B is f, and the length of C D is h.

Because △ABC and △CBD both have a right angle, and the same angle B is in both triangles, the triangles must be similar by AA. Likewise, △ABC and △ACD both have a right angle, and the same angle A is in both triangles, so they also must be similar by AA. The proportions StartFraction c Over a EndFraction = StartFraction a Over f EndFraction and StartFraction c Over b EndFraction = StartFraction b Over e EndFraction are true because they are ratios of corresponding parts of similar triangles. The two proportions can be rewritten as a2 = cf and b2 = ce. Adding b2 to both sides of first equation, a2 = cf, results in the equation a2 + b2 = cf + b2. Because b2 and ce are equal, ce can be substituted into the right side of the equation for b2, resulting in the equation a2 + b2 = cf + ce. Applying the converse of the distributive property results in the equation a2 + b2 = c(f + e).

Which is the last sentence of the proof?

Because f + e = 1, a2 + b2 = c2.
Because f + e = c, a2 + b2 = c2.
Because a2 + b2 = c2, f + e = c.
Because a2 + b2 = c2, f + e = 1.

Answers

Answer:

I don't know how I can help you but I found this from another person. Hope this helps!

Answer:

The answer is b

Step-by-step explanation:

Consider the diagram and the paragraph proof below.

Given: Right △ABC as shown where CD is an altitude of the triangle

Prove: a2 + b2 = c2

 Triangle A B C is shown. Angle A C B is a right angle. An altitude is drawn from point C to point D on side A B to form a right angle. The length of C B is a, the length of A C is b, the length of A B is c, the length of A D is e, the length of D B is f, and the length of C D is h.

Because △ABC and △CBD both have a right angle, and the same angle B is in both triangles, the triangles must be similar by AA. Likewise, △ABC and △ACD both have a right angle, and the same angle A is in both triangles, so they also must be similar by AA. The proportions StartFraction c Over a EndFraction = StartFraction a Over f EndFraction and StartFraction c Over b EndFraction = StartFraction b Over e EndFraction are true because they are ratios of corresponding parts of similar triangles. The two proportions can be rewritten as a2 = cf and b2 = ce. Adding b2 to both sides of first equation, a2 = cf, results in the equation a2 + b2 = cf + b2. Because b2 and ce are equal, ce can be substituted into the right side of the equation for b2, resulting in the equation a2 + b2 = cf + ce. Applying the converse of the distributive property results in the equation a2 + b2 = c(f + e).

Which is the last sentence of the proof?

Because f + e = 1, a2 + b2 = c2.

Because f + e = c, a2 + b2 = c2.

Because  a2 + b2 = c2, f + e = c.

Because  a2 + b2 = c2, f + e = 1.

The graph shows the distance you and your friend drive on a trip. Find the slope of your line. For your answer, just type the number. *

Answers

Answer:

there is no picture

Step-by-step explanation:

im sorry

A $250 Suede Jacket is on sale for 20% off. How much should you pay for the jacket?

Answers

Answer:

If the jacket is on sale for 20% off, you are paying 80% of the price.

So, 0.8(250), which is 200 dollars.

Let me know if this helps!

Answer:

$200

Step-by-step explanation:

First you have to figure out how much 20% is. (Its $50) So now, all you have to do it 250-50 which is $200

Help, ill give brainliest to those who answer first and those who answer accurately

Answers

Answer:

d

Step-by-step explanation:

30 cm. I hope this helps!

Find the values of the variables in parallelogram ABCD

Answers

x=4 y=1

Step-by-step explanation:

An advertising agency notices that approximately 1 in 50 potential buyers of a product ssees a given magazine ad, and 1 in 5 sees a corresponding ad on television. One in 100 see both. One in 3 actually purchases the product after seeing the ad, 1 in 10 without seeing it. What is the probability that a randomly selected potential customer will purchase the product

Answers

Answer:

0.1490 = 14.90% probability that a randomly selected potential customer will purchase the product.

Step-by-step explanation:

Probability of seeing the ad:

I am going to find this probability using Venn Sets.

I am going to say that:

Event A: Sees a magazine ad.

Event B: Sees a television ad.

Approximately 1 in 50 potential buyers of a product sees a given magazine ad

This means that [tex]P(A) = \frac{1}{50} = 0.02[/tex]

1 in 5 sees a corresponding ad on television.

This means that [tex]P(B) = \frac{1}{5} = 0.2[/tex]

One in 100 see both.

This means that [tex]P(A \cap B) = \frac{1}{100} = 0.01[/tex]

The probability of seeing the ad is the probability of seeing at least one of those(magazine or tv), which is:

[tex]P(A \cup B) = P(A) + P(B) - P(A \cap B)[/tex]. So

[tex]P(A \cup B) = 0.2 + 0.02 - 0.01[/tex]

[tex]P(A \cup B) = 0.21[/tex]

Probability of purchasing the product.

0.21 = 21% of customers see the add. Of those, 1/3 = 0.3333 buy the product.

1 - 0.21 = 0.79 = 79% of customers dont see the add. Of those, 1/10 = 0.1 buy the product. So

[tex]p= 0.21*0.3333 + 0.79*0.1 = 0.1490[/tex]

0.1490 = 14.90% probability that a randomly selected potential customer will purchase the product.

3X^2+3 and 4x^2-1 Enter your answer in simplest form in the boxes.

Answers

Answer:

(12) (x^4) (2)

Hope it helps.

Step-by-step explanation:

(3x^2 + 3) (4x^2 - 1)

(3 x 4) (x^2 X x^2) (3 - 1)

(12) (x^4) (2)

Sanjay, Ajay and Anushka are employees of a company that has branches in Chennai, Bangalore and Mumbai. The company sends each of them to one of these cities at random. Let X X be a random variable that denotes the number of employees assigned to their favourite cities. If Chennai, Bangalore and Mumbai are the favourite cities of Sanjay, Ajay and Anushka, respectively, then find the possible values of X.

a. X= {0,1,2}
b. X= {0,1,2,3}
c. X= {0,1,3}
d. X= {0,[infinity]}

Answers

Answer:

c. X= {0,1,3}

Step-by-step explanation:

We have these possible outcomes:

None assigned to their favorite cities.

One assigned to their favorite city(The other two are assigned to the other's favorite city).

All are assigned to their favorite city.

Why is two not possible?

If two peooke are assigned to their favorite city, the third person necessary has to be assigned to their favorite city, as it will be the only option remaining.

So the correct answer is given by option c.

What is the y intercept of the line?


-3


1


5


-2

Answers

-3 is where the line hits the y axis, hope this helped

Can someone help me please help pls thank you so much

Answers

Answer:

B

Step-by-step explanation:

To answer this question, you simply have to keep track of the numbers given and make sure that there is an 'X' for each number where it belongs. By looking at the line plots, we can say that the answer is:

Chart B

Hope this helps :)

An engineer is planning a new water pipe installation. The circular pipe has a diameter of d = 20 centimeters. What is the area (A) of the circular cross section of this pipe?
║Give your answer in terms of ⫪║

Answers

Answer:

radius=diameter/2=20/2

=10cm/100=0.1m

Area of a circle=πr^2

A=π×0.1×0.1

A=0.01πm^2

Find the equation of the line with slope –5/2
and y-intercept (0,0).

Answers

Answer:

y= -5/2X

.....................

please help guys, this is due today.

Answers

Answer:

-0.58 is the answer

Step-by-step explanation:

The school play earned $11,271 in ticket sales. If the cost of each ticket was $13, how many tickets were sold?

Answers

Answer:

867 tickets were sold because if you divide how much they earned by how much it cost you get 867

Answer:

867 Tickets

Step-by-step explanation:

Divide $11,271 by the number of the ticket cost $13.

11,271/13= 867

. The function is shown belo [tex]y=2^x[/tex] If the function is translated 4 units up, which of the following will represent the y-intercept and the equation of the horizontal asymptote of the translated function?

Answers

Answer: (0,5); y= 4

Step-by-step explanation:

Solve for x and y. Please help, I will mark as brainliest and give many points

Answers

Answer:

x=13 y=25

Step-by-step explanation:

Answer:

x = 30°, y = 45°, w = 14√2, v = 7√2

Step-by-step explanation:

ΔABC has AB = 2BC, hypotenuse is twice the leg

⇒ x = 30°

ΔBCD is isosceles right triangle

⇒ y = 45°

ΔMPN is isosceles right triangle (∠M = 45°)

⇒ w = MN = √2PN = 14√2

ΔMKP is isosceles right triangle (∠M = 45°)

v= KP = MK = 1/2MN = 1/2(14√2) = 7√2

Can somebody please answer my question

Answers

Answer:

x≥-6

Step-by-step explanation:

which function defines (f divided by g)(x)

Answers

Answer:

A if its wrong im sorry

Step-by-step explanation:

The function is (f ÷ g) (x) is given as [tex](3.6)^{-2x + 1}[/tex]. Then the correct option is A.

What is a function?

The function is an expression, rule, or law that defines the relationship between one variable to another variable. Functions are ubiquitous in mathematics and are essential for formulating physical relationships.

The functions are given as

[tex]\rm f(x) = (3.6)^{x + 2}\\\\\\g(x) = (3.6)^{3x + 1}[/tex]

The f(x) is divided by the g(x), we have

[tex]\rm (f \div g ) (x) = \dfrac{f(x)}{g(x)} = \dfrac{(3.6)^{x + 2}}{(3.6)^{3x + 1}}\\\\\\(f \div g ) (x) = (3.6)^{x + 2}*(3.6)^{-(3x + 1)}\\\\\\(f \div g ) (x) = (3.6)^{x + 2- 3x - 1}\\\\\\(f \div g ) (x) = (3.6)^{-2x + 1}[/tex]

More about the function link is given below.

https://brainly.com/question/5245372

A graphing calculator is recommended. A bacteria culture starts with 300 bacteria and doubles in size every half hour. (a) How many bacteria are there after 2 hours? bacteria (b) How many bacteria are there after t hours? y = bacteria (c) How many bacteria are there after 40 minutes? (Round your answer to the nearest whole number.)

Answers

Answer:

a) 4800 bacteria

b) [tex]y(t) = 300(4)^t[/tex]

c) 754 bacteria

Step-by-step explanation:

A bacteria culture starts with 300 bacteria and doubles in size every half hour.

This means that the number of bacteria after t periods of half hour is given by:

[tex]y(t) = 300*(2)^{t}[/tex]

(a) How many bacteria are there after 2 hours?

2 hours is 2*60/30 = 4 periods of 2 hours, so this is y(4).

[tex]y(4) = 300*(2)^{4} = 300*16 = 4800[/tex]

(b) How many bacteria are there after t hours?

It doubles every half hour, so each hour, it is multiplied by 4. Then

[tex]y(t) = 300(4)^t[/tex]

(c) How many bacteria are there after 40 minutes?

40 minutes is 40/30 = 1.33 periods of half hour. So this is y(1.33).

[tex]y(1.33) = 300*(2)^{1.33} = 754[/tex]

Twice a number is 17

Answers

Answer:

Twice a number is 17=2×17=34

8.5

8.5=8.5=17

8+8=16

.5+.5=1

16+1=17

from the set 1/2/3/4/5 which values make the inequality n + 1 > true?

Answers

Hi there!

To make n+1>4 true, you must have n be a numebr greater than 3...

The reason why is because if it is less than 3 or 3, it’ll have to be <.

The two numbers that can make this equation true is 4 and 5...

[tex]4+1=5>4[/tex]

[tex]5+1=6>4[/tex]

And if it is 1,2, and 3 it would be:

[tex]1+1=2<4[/tex]

[tex]2+1=3<4[/tex]

[tex]3+1=4=4[/tex]

(6x - 3y) -2(x + 4y)

Answers

Answer:

4x-11y

Step-by-step explanation:

How to solve your question

Simplify

(6−3)−2(+4)

(6x-3y)-2(x+4y)

(6x−3y)−2(x+4y)

Distribute

(6−3)−2(+4)

(6−3)−2−8

Eliminate redundant parentheses

(6−3)−2−8

6−3−2−8

Combine like terms

6−3−2−8

4−3−8

Combine like terms

4−3−8

4−11

4(10-x)=40-4x is one solution

Answers

Answer:

( -infinity, infinity)

Step-by-step explanation:

any value of x is true

I will give 15 points and brainliest for this answer

Answers

Here is your answer:

Find the scale factor from polygon ll to polygon lin the following figures. 9 150° 150° 3 6 6 2150° 150° 2 60° I 60° 60° II 60° 2 150° 150° 2 6 6 150° 150° 3 9​

Answers

Remember, SF= new/old. On shape 2, the side with the length 3 corresponds to the length of 9 on shape 1. (SF=3/9)=0.3333333....

factor this polynomial x^2 -3x^3 +10x^7

Answers

x^2 (1-3x+ 10x^5)
pls mark brainliest if correct

Help me out , please I forgot how to do this mathematics

Answers

Answer:

C

Step-by-step explanation:

sorry if I'm wrong-

3x + 2x – x + 2x² + 4

Answers

Answer:

Step-by-step explanation:

Combine like terms, in this case there is only x

[tex]3x+2x-x+2x^2+4\\4x+2x^2+4\\2x^2+4x+4\\2(x^2+2x+2)[/tex]

Help me with this one please, the highlighted one is wrong.

Answers

Answer:

d

Step-by-step explanation:

i did this before so i pretty much know

What is the value of n in 2n+1=3

Answers

2n+1=3
2n=3-1
2n=2
n=1 is the answer

Answer:

n=1

Step-by-step explanation:

2n+1-1=3-1

2n=2 divide both sides by two

n=1

 can i get brainliest please???

it would be very much appreciated

have a nice day :)

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